Engine driven welding machines include a gas powered engine to run a generator which supplies power to the welding electrode. Two such engine welders are disclosed in U.S. Pat. Nos. 6,296,027 and 6,172,332, both of which are incorporated herein by reference. The generator can also be used to operate other electrical equipment (e.g., lights, pumps, etc.). On a construction site, welding equipment and other types of equipment are commonly used. The engine driven welder is commonly used to provide electrical power to electric welders, lights, power tools, etc. Air powered tools are also commonly used at a construction site. Such tools are typically powered by a separate air compressor.
While both of these units have satisfactorily provided power to various tools at construction sites, the use of both an air compressor and an engine driven welder has some disadvantages. Although the engine welder and air compressor are portable, it is nevertheless difficult and time consuming to load and unload these two separate units, and then position and setup the various components which are to be used with such units. In addition, the two separate units require a certain amount of space in a transport vehicle, thus can result in multiple vehicles having to be used to transport all the components associated with the two units. Furthermore, some air compressors are powered by electricity. When such electric compressors are used at a work site, the air compressor may be plugged into and powered by the generator of the engine welder, thus reducing the available power for use with other power tools.
In an effort to address the past problems associated with the use of a separate engine welder and air compressor, a self contained integrated welder/generator and compressor is disclosed in U.S. Pat. No. 6,051,809, which is incorporated herein by reference. The '809 patent discloses a self-contained and fully integrated welder/generator and compressor unit that is capable of being loaded onto and carried by a pickup truck. The welder/generator and compressor unit include a housing having a length that generally corresponds to the width of a pickup truck and having a vertical height for receiving and containing components of the welder/generator and compressor unit (e.g., compressor, generator, welder electronics, engine, fuel tank, etc.). An engine and an electrical current generating alternator are mounted within the housing of the welder/generator and compressor unit. The electrical current generating alternator is connected to the engine to be driven thereby, and the alternator includes an output drive shaft that drives a belt which in turn powers an air compressor. The housing includes an output panel that includes electrical outlets, welding lead receptacles, air compressor outlets, etc.
Although the '809 patent addresses some of the disadvantages associated with a separate engine welder and air compressor, several problems still remain. The housing of the welder/generator and compressor unit is specifically designed to fit in the rear of a pickup truck. If the pickup truck cannot be positioned near a particular work site, the welder/generator and compressor unit must be removed from the pickup truck and carried to the particular work site. Furthermore, the '809 patent discloses that the air compressor is connected to the shaft of the alternator by a belt which can require periodic maintenance. In addition, belt drives typically include a crankshaft pulley(s) and may use a magnetic clutch to control the belt drive. These components have a tendency to quickly wear out, thereby requiring periodic maintenance.
Another engine welder and air compressor is disclosed in United States Patent Application Publication No. 2003/155,339 published on Aug. 21, 2003 entitled “Screw air compressor for a welder”, which is incorporated herein by reference. The '399 patent publication discloses welder having an internal screw air compressor that is belt driven by the engine in the housing of the engine welder. The engine is designed to work in conjunction with a has a pulley arrangement connected by belts to drive the screw air compressor, an alternator, and an engine cooling fan. A clutch assembly connected to the screw air compressor to control the screw air compressor. As previously discussed, such an arrangement tend to quickly wear out, thereby require periodic maintenance.
Assignee's U.S. patent application Ser. No. 10/390,436 filed Mar. 17, 2003, now U.S. Pat. No. 6,989,509, discloses an integrated welder and compressor unit that overcomes the past problems with these prior welder and compressor units. The integrated engine driven welder and compressor unit disclosed in the '436 patent application can be conveniently transported to a site for welding, operating air and/or electric power tools, and is more easily operated and maintained by a user. The integrated engine driven welder and compressor unit disclosed in the '436 patent application discloses an air compressor connected to the drive shaft of the engine and/or electrical alternator by a gear box. The gear box can have a single gear ratio or multiple gear ratios to thereby control the desired speed of the compressor. The use of the gear box eliminates the need for a belt that must be periodically replaced and/or the tension being periodically adjusted as was required in prior art designs. The use of the gear box also allows the speed of the compressor to be better controlled. The use of the gear box typically simplified and/or reduced the space requirements needed to connect the compressor to the drive shaft of the engine and/or electrical alternator, thus simplifying the assembly of the integrated welder/generator and compressor unit by reducing the number of components needed to connect the gear box between the air compressor and the engine and/or electric current generator. The use of the gear box also resulted in reduced cost due to the simpler design and fewer parts. The use of the gear box further resulted in less maintenance since the gear box is more durable than a belt and pulley system, especially one that utilizes one or more clutches.
Although the integrated engine driven welder and compressor unit disclosed in the '436 patent application was a significant improvement over prior art integrated engine driven welder and compressor units, the use of a gear box to drive the compressor unit limits the location in which the compressor can be positioned in the housing of the engine welder. In order to minimize the space and positioning limitations within the welder housing, special or more complex gearing arrangements are required. Air compressors that are powered by gears are also typically more expensive than electric powered air compressors due to the more complex design of the gear and belt powered compressors.
In view of the limitations of integrating a gear powered air compressor with an engine welder, there remains a need for an integrated engine driven welder and compressor unit that can provide both electrical power and air pressure for use by various types of tools at a work site, that enables the air compressor to be ergonomically positioned within the housing of the engine welder, and that simplifies the design and reduces manufacturing cost for the integrated engine driven welder and compressor unit.